In 1978 I was taught how to do the monthly reset on the American version of the Enigma machine while at COMSUBLANT. At that time it was the ‘back up’ to the systems using IBM ‘encryption’ cards and those card readers.
I was told we kept the mechanical encripters a long time. Because the keyboards of the electronic version emitted plain text and was suspect on security.
Of course in today’s world it is all micro-burst spread spectrum.